It is generally known that the above-mentioned type of optically active compounds are obtainable through optical resolution of racemate or an asymmetric synthetic route. Conventional routes require, however, some special reagents or enzymes, or sometimes cumbersome steps. Furthermore, only a few methods for optical resolution of this type of compounds can give high optical purity enough for practical use.
Therefore, obtaining compounds of high optical purity is extremely important for synthesizing various compounds e.g., medicaments.